赖氨酸脱羧酶分子改造及固定化合成1,5-戊二胺研究进展

Molecular engineering and immobilization of lysine decarboxylase for synthesis of 1,5-diaminopentane: a review

摘要:

1,5-戊二胺又名尸胺，是一种重要的生物基聚酰胺生产原料，可以与二元羧酸缩合生成生物基聚酰胺PA5X，其性能可以与石油基聚酰胺材料媲美。生物基聚酰胺以可再生能源为底物，如淀粉、纤维素、植物油等，符合绿色可持续发展战略。1,5-戊二胺的生物合成主要包括微生物从头合成及全细胞催化两种方法，而赖氨酸脱羧酶是其生物合成中的关键酶，该酶主要包括诱导型赖氨酸脱羧酶CadA和组成型赖氨酸脱羧酶LdcC两种。赖氨酸脱羧酶是一种折叠型Ⅰ型磷酸吡哆醛(pyridoxal-5' phosphate,PLP)依赖酶，但该酶在实际反应过程中易受环境因素影响，存在活性不高、结构不稳定等问题。因此，提高赖氨酸脱羧酶催化活性及稳定性成为该领域的研究热点，主要包括分子改造以及固定化研究。文中综述了赖氨酸脱羧酶的作用机理、分子改造技术及固定化策略的研究进展，并对未来进一步提升赖氨酸脱羧酶活性及稳定性策略进行了展望，旨在实现1,5-戊二胺的高效生物制备。

Abstract:

1,5-diaminopentane, also known as cadaverine, is an important raw material for the production of biopolyamide. It can be polymerized with dicarboxylic acid to produce biopolyamide PA5X whose performances are comparable to that of the petroleum-based polyamide materials. Notably, biopolyamide uses renewable resources such as starch, cellulose and vegetable oil as substrate. The production process does not cause pollution to the environment, which is in line with the green and sustainable development strategy. The biosynthesis of 1,5-diaminopentane mainly includes two methods:the de novo microbial synthesis and the whole cell catalysis. Lysine decarboxylase as the key enzyme for 1,5-diaminopentane production, mainly includes an inducible lysine decarboxylase CadA and a constituent lysine decarboxylase LdcC. Lysine decarboxylase is a folded type Ⅰ pyridoxal-5' phosphate (PLP) dependent enzyme, which displays low activity and unstable structure, and is susceptible to deactivation by environmental factors in practical applications. Therefore, improving the catalytic activity and stability of lysine decarboxylase has become a research focus in this field, and molecular engineering and immobilization are the mainly approaches. Here, the mechanism, molecular engineering and immobilization strategies of lysine decarboxylase were reviewed, and the further strategies for improving its activity and stability were also prospected, with the aim to achieve efficient production of 1,5-diaminopentane.